Woven cotton-polyester blend fabrics having recoverable stretch characteristics



Dec. 13, 1966 w QRMAND 3,290,752 WOVEN COTTON-POLYESTER BLEND FABRICSHAVING RECOVERABLE STRETCH CHARACTERISTICS Filed March 26, 196:5

WOVEN FABRIC CONSISTING OF BLEND OF COTTON AND POLYESTER FIBER DESIZEFABRIC WET FABRIC WITH MERCERIZING SOLUTION 0E SODIUM HYDROXIDE SHRINKFABRIC IN FILLING DIRECTION BY ACTION 0}? MERCERIZING AGENT WHILESUBSTANTIALLY UNTENSIONED IN FILLING DIRECTION BUT MAINTAINING TENSIONIN WARPWISE DIRECTION WASH FABRIC WITH TENSION IN WARPWISE DIRECTION BUTWITHOUT TENSION INEILLLNG DIRECTION AND DRY WITHOUT STRETCHING INFILLING DIRECTION IMPREGNATE FABRIC WITH A LIQUID MIXTURE OF FLUORESCENTDYE AND WETTING AGENT, AND DRY WHILE RESTRICTING SHRINKAGE IN FILLINGDIRECT ION HEAT DRIED FABRIC TO SHRINKAND STABILIZE POLYESTER FIBERSOFFILLING YARNS WHILE MAINTAINING FABRIC UNDER TENSION IN WARPWISEDIRECTION BUT WITHOUT TENSION IN FILLING DIRECTION IMPREGNATE. FABRICWITH LIQUID MIXTURE OF SOFTENER AND PIGMENT AND DRY WHILE CONTROLLINGWIDTH SUBJECT FABRIC TO COMPRESSIVE SHRINKAGE OPERATION '10 CONTROLRESIDUAL SHRINKAGE INVENTOR HARRY W. ORMAND ATTORNEYS United StatesPatent 3,290,752 WOVEN COTTON-POLYESTER BLEND FABRICS HAVING RECOVERABLESTRETCH CHARAC- TERISTICS Harry W. Ormand, Upson County, Ga., assignorto Thomaston Cotton Mills, Thomaston, Ga., a corporation of GeorgiaFiled Mar. 26, 1963, Ser. No. 267,932 5 Claims. (Cl. 28--74) Thisinvention relates to woven fabrics comprising blends of cotton andsynthetic fibers having recoverable stretch characteristics, and isparticularly directed to the production of cotton-polyester blendfabrics woven from standard or normal twist yarns which have desirablestretch properties in the filling direction.

A primary object of the invention is to provide a simple but elfectiveprocess for manufacturing woven cottonpolyester blend fabrics wherebystabilized width stretch characteristics are embodied therein by anovelcombination of mechanical and chemical treating steps Without usingstretch or textured yarns, and without requiring special machinery.

Another object is the provision of a new and economical method forproducing fabrics woven of cotton and polyester fibers having highstretch and recovery properties in the filling direction wherein onlystandard or normal twist yarns are employed.

A further object is to produce woven cotton-synthetic blend fabrics ofimproved stretch characteristics which.

are especially well adapted for end use in the apparel field, for suchitems as shirts, pajamas, brassiere fabrics, outerwear, underwear,lounge wear, sportswear, foundation garments, shoes, bathing suits andcoating for rainwear, and for such industrial end uses as themanufacture of vinyl, rubber, pyroxylin and polyurethane coated orlaminated textile materials, where resiliency in one direction is-animportant consumer quality.

In accordance with the present invention, woven cotton and polyesterblend fabrics having a stretch of from 15% to 30% in the width can beproduced simply and economically, using conventional finishingmachinery, by a novel combination of chemical and mechanical treatingsteps including mercerizingwithout widthwise tension, Washing in openwidth washers, drying without increasing the width of the fabric,treating with a resin or other chemical agent so as to stabilize thecotton fibers, or, alternatively, heat setting to shrink and stabilizethe polyester fibers;v and compressively shrinking the fabric to controlthe residual shrinkage. In addition to these principal steps, theprocess may include various other operati-ons as will appear morefully'from the examples herein after described.

The process of the invention is applicable to all woven cotton-polyesterblend fabrics made from standard or normal twist yarns, including reededout or redesigned constructions as well as standard greige constructionsof various types and weights. The product of the invention is a wovencotton-synthetic fabric having a high degree of stretchab'ility andelastic recovery in the filling direction while being relativelyunstretchable in the warp direction, and is useful for a wide variety ofend uses either per se or as a backing for or lamina with such othermaterials as vinyl plastic and rubber sheeting, polyurethane foams,pyroxylin artificial leather and the like.

I have discovered that woven cotton-polyester blend fabrics of highwidth stretch and low set characteristics can be produced by shrinking adesized greige or bleached fabric in the filling direction by subjectingit to the action of a mercerizing agent without widthwise restraintwhile maintaining it under tension in. a lengthwise direction,

thereafter washing the fabric until substantially all of the mercerizingagent has been removed, again without applying tension in the fillingdirection, drying the washed fabric without stretching widthwise,impregnating the dried fabric with a thermosetting resin or othersuitable cross linking agent and curing the resin so as to maintain thecotton fibers of the fabric in resilient or elastic condition in theWidth, washing the resin treated fabric with a suitable detergent toremove any unfixed resin or other free chemicals, drying, top softeningthe dried fabric and then again drying on a tenter frame, and finallyshrinking the fabric on a compressive shrinking machine so as to controlthe residual shrinkage and produce the desired finished width. I havealso found that similar high width stretch and low set characteristicscan be obtained by substituting for the resin treatment, which affectsonly the cotton fibers of the fabric, a heat setting operation whichaffects only the polyester fibers.

The term low set characteristic as used herein has reference to thatcharacteristic of the fabrics of the present invention which isrepresented by the ability of the fabric to undergo repeated stretchingwithout suffering more than a relatively small amount of permanentelongation in the stretched direction. In other words, low set is theequivalent of high recovery. A method of measuring the set of stretchfabric is described hereinafter in connection with Example I.

The desired results may be effectively obtained by a process whichincludes the following steps. First, after a cotton-polyester blendfabric of suitable construction and weight, such as a 50% cotton and 50%Kodel blend, has been desized, scoured, bleached, singed and dried, itis impregnated with an aqueous solution of sodium hydroxide ofmercerizing strength, a solution having a specific gravity of from 52 to54 Twad. being preferred, and is then advanced through a mercerizingrange under warpwise tension but free from tension in the fillingdirection and without using water on the tenter frame. The fabric isthus free to shrink widthwise under the effect of the mercerizingsolution and as a result of the lengthwisetension which is maintained toprevent shrinkage in the warp direction. After the fabric has beensaturated with the mercerizing solution, it is washed with water toremove the sodium hydroxide while tensioned in the warp direction butagain left slack in the filling direction, the washing preferably beingcarried out by advancing the fabric through a plurality of open widthwashers, using water of any suitable temperature. Ordinarily hot waterhaving a temperature of from about 160 to about 180 F. is used in allbut the last washer wherein cold water is used. If desired, a smallamount of acid may be added to the water in the next to the last Washerin order to neutralize any of the caustic soda which may remain in thefabric. After the washing operation, the fabric is dried in a revolvingdrum or can type drier without increasing the width thereof while stillapplying tension in a warpwise direction.

Alternatively, in the event that the widthwise shrinkage due to chemicalaction is to be accurately limited to a predetermined amount, theselvages of the fabric may be attached to the appropriately adjustedpins or clips of the mercerizing tenter frame during passagetherethrough so that the fabric may not shrink more than the desiredamount. Normally, however, the method of the present inventioncontemplates the maximum possible shrinkage of the fabric in the fillingdirection, i.e., up to about 30%, the amount of shrinkage beingcontrolled by both the strength of the mercerizing solution andthelengthwise tension applied to the fabric.

Instead of impregnating the fabric with sodium hydroxide on aconventional mercerizing range as above described, this step of themethod may be carried out by passing the fabric in a slack widthcondition through a suitable padding apparatus equipped with asaturating box and then winding the goods on a roll under lengthwisetension for a suitable period of storage before the washing step.

After the fabric has been slack mercerized, washed and dried, it ischemically treated with a cross linking agent in order to stabilize thewidth stretch properties then possessed by the cotton fibers of thegoods as a result of the abnormal shrinkage previously produced. Forthis purpose, the fabric may be first treated with an anionic wettingagent and then impregnated with a suitable thermosetting resin andcatalyst, dried without increasing the width thereof, and subjected toan elevated temperature of such amount, and for such a period of time,as will effect proper curing of the resin. Triazine or triazone resinsand buffered inorganic salt catalysts, such as magnesium chloride, arepreferred, in which event curing at a temperature of from 320 to 340 F.for a period of from one to three minutes will normally sufiice.Alternatively, the resin may be replaced by a non-resin cross linkingagent, such as formaldehyde, divinyl sulfone, and other known chemicalshaving the capacity to react with and cross link the cellulose moleculesof cotton fibers.

Following the cross linking treatment, the fabric is soaped or washedwith a detergent of any suitable composition in order to remove excesschemicals which may remain from the preceding steps, dried, top softenedby passage through a mix containing suitable softeners, lubricants and avat pigment, and then dried on a tenter frame. After this last dryingstep, the fabric is shrunk on a compressive shrinking machine to providea 1% residual shrinkage in the length and sufficient shrinkage in thewidth to produce the desired finished width.

When processing certain types of cotton-polyester blend fabrics, such asa blend of 35% cotton and 65% Dacron, it may be desirable to omit thecross linking treatment and instead subject the fabric to a heat settingoperation. In this modification of the process, after the fabric hasbeen mercerized, washed and dried, it is padded through a bluing mixcontaining a fluorescent dye and then dried by passage through a tenterframe equipped with a drying system under lengthwise tension but withoutany tension in the filling direction, or with a width setting which isfrom 2 to 3" greater than the desired finished width of the goods. Fromthe drying tenter frame, the fabric is passed through a heat settingoven at such a temperature and speed of travel as to shrink andstabilize the polyester fibers of the fabric. Following the heat settingoperation, the goods are treated with softeners, lubricants and dyes ofany suitable character, dried, and finally shrunk on a compressiveshrinking machine as previously described.

The invention will now be more specifically described by reference tothe following illustrative examples.

Example I and proteolytic enzymes, such as Rapidase 800, at atemperature of approximately 150 F., after which the fabric was scouredin rope form through hot water containing 4 pounds of soda ash per 100gallons at a temperature of approximately 160 F., so as to remove thewater soluble sizing from the goods, together with dirt, soil and otherundesirable substances. From the scouring vessel, the fabric wastransferred on reels to a bleaching kier into which was introduced ableaching solution containing 75 pounds of 35% hydrogen peroxide and 150pounds of sodium silicate per 1000 gallons of water. The bleachingliquor was heated to about 190 F. and then held at that temperature andcirculated within the kier for about 5 hours. At the end of this time,the spent liquor was drawn off from the kier and the bleached goods werewashed in rope form, water mangled and dried. The dry bleached fabricwas then singed to remove the projecting cotton and polyester fibers inorder to control pilling or balling up of the polyester fibers, and toimprove the appearance of the goods. 7

The desized, bleached and singed fabric was next impregnated with a 5254Twad. solution of sodium hydroxide at approximately room temperature andsqueezed on a three-roll mercerizer pad, and then run through the tenterframe of a mercerizing range at a speed of about 50 yards per minutewith the frame set from 3 to 6 under the grey width of the goods andwith the washing system shut off so as to permit free shrinkage of thefabric in the filling direction. In this connection, it will beunderstood that the widthwise shrinkage of the fabric is produced bothby the chemical action of the mercerizing solution and mechanically byreason of the fact that lengthwise tension is applied to the fabric, asby means of drag or tension bars and compensator rolls, continuouslyduring passage of the goods through the mercerizing range as well asthrough the desizing pad box.

From the tenter frame, the goods were run through a series of open widthWashers to remove the sodium hydroxide, passing twice through aseven-box washer fed with hot water at a temperature of approximately180 F. and at a rate of 70- gallons per minute, and were then dried bypassage through a drier of the steam heated revolving drum or can type,without any increase in width.

After drying, at which time the width of the goods had shrunk to 39%",the fabric was treated with resin in order to stabilize the recoverablestretch characteristics of the finished goods. To this end, the fabricwas padded through a resin mix on a two-roll pad, the mix containing,per gallons of mix:

48 pounds of a triazone thermosetting resin, such as St-anset.

10 pounds of a buffered inorganic salt catalyst, such as the magnesiumchloride Catalyst 100.

1 pound of a suitable wetting agent, such as the alky-laryl polyglycolether Standapon 95.

1300 cc. of a dispersed blue vat pigment, such as GAPZ.

4500 cc. of an optical whitener fluorescent dye, such as BlancophorHS-31.

750 cc. of another fluorescent dye, such as Uvitex.

10 pounds of a self-emulsifying fatty-based ester derivative softenerand lubricant, such as Cream 445.

After padding through the resin mix, the goodsiwere passed into a heatedtenter frame set, in this instance, at a width of 43 inches, where theywere dried. From the tenter frame, the dried fabric was passed through acuring oven at the rate of yards per minute, the temperature in the ovenbeing about 340 F. and the curing time being approximately 72 seconds.The width of'the goods leaving the curing oven was 41 /2".

At this stage of the process, the fabric possessed the desired highwidth stretch and recovery properties. However, in order to remove anyresidual objectionable chemicals, such as unfixed resin, the goods weresoaped, i.e., treated with a detergent, by passing them through fouropen width wash boxes containing an aqueous mixture of 2 pounds of'alkylphenoxypoly ethanols per 600 gallons of water, heated to atemperature of approximately 180 F and then through three boxes of hotwash water of substantially the same temperature. After the soaping, thefabric was dried on steam heated drying cans, and then further treatedby passage through a top softening mix on a two roll pad, the mixcontaining per 100 gallons of mix:

20 pounds of a self-emulsifying fatty-based ester derivative softenerand lubricant, such as S-916.

40 pounds of another softener and lubricant, such as No. 735.

200 cc. of a vat pigment in dispersed form adapted to enhancethe shadeof white, such as Violet.

Upon leaving the top softening pad, the goods were again dried on atenter frame.

In all of the drying steps above mentioned other than thatfollowing theresin impregnation, it will be understood that the fabric was free fromtension in the filling direction, although continuously under tension inthe warp direction.

As the final step in the process, the fabric was shrunk on a compressiveshrinking machine to provide a 1% residual shrinkage in length and therequired shrinkage in width to produce a finished width of from 40 to41".

Samples were then cut from the center section of the finished goods forlaboratory testing as respects stretch ,and set, each sample being 3" x9 with the 3f measurement slightly oversized so that, after unravellingthe filling threads, the filling width was 3". Two clear lines or benchmarks 3" apart were marked across the sample, and a clamp was placed oneach end. The clamp'at one end was fastened to a bench while a 27 poundweight was attached to the clamp at the other end and suspendedvertically fora period of minutes. At the end of the 10 minuteperiod,the increase in length of the 3" marked section was measured andcalculated as the percent of stretch. After removing the weightandallowing the sample to recover" in a horizontal position for tenminutes, the increase in length of the 3" section was remeasured andcalculated as the percent of set.

When the fabric "of the present example was tested in this manner, thefollowing results were obtained:

Stretch Set Shrinkage I 4l Warp Filling Warp Filling Warp Filling ,Norn:Shrinkage indicates a gain.

It will also be understood that all of the test results herein set forthrepresent the average of several tests on samples taken from differentrolls of the same finished lot, and are subject to normal variationswithin 1% or 2%.

Example II 'A'lot of 48%" wide 3.91 yards per pound 96 x 84 unbleachedfabric made up of a blend of 50% cotton and 50% Kodel polyester fiberswas desized, bleached, singed, mencerized, washedand dried in the samemanner as that described in Example I, and a ain the width of the fabricafter drying-had shrunk to' 39% I o After drying, the -fabric was paddedthrough a bluing mix-on a two roll pad,-the mix containing per 100gallons of'mix:

300 cc. of an optical whitener fluorescent dye, such as BlancophorHS-3-1. i 1

700 0c. of-another'fluorescentdye, such as Uvitex.

1 poundofa suitable wetting agent, such as the sodium alkylnaphthalenesulfonate- Nekal.

After padding through the bluingmix, the goods were dried on a heatedtenter frame having a width setting of 43". From the tenter frame, thefried fabric was passed through a heat setting oven at the rate of 125yards per minute, the goods being maintained under tension in the wanpdirection but without tension in the filling direction, the temperaturein the oven being approximately 385 F., and the heat settingtime beingabout 63 seconds. The width of the goods leaving the heat setting ovenwas 40%", indicating a decrease of approximately 2% duringthe' heatsetting operation. This decrease in Width resulted from both-themechanical tension on the warp in the absence of widthwise tension andthe shrinkage effect of the heat on the polyester fibers in the filling.The heat setting process also imparted stability to the polyester fibersas respects shrinkage and wash-and-wear qualities.

Following the heat setting operation, the fabric was treated by paddingon a two roll pad through a finishing mix containing, per gallons ofmix:

20 pounds of a self-emulsifying fatty-based ester derivative softenerand lubricant, such as S-916.

40 pounds of another softener and lubricant, such as No. 735.

400 cc. of a vat pigment in dispersed form adapted to enhance the shadeof white, such as Violet.

1 pound of a suitable wetting agent, such as the alkylaryl polyglycolether Standapon 95.

cc. of an optical whitener flourescent dye, such as Blancophor HS-3l.

400 cc. of a blue vat pigment dispersion adapted to add a blue tint tothe shade of white.

Upon leaving the finishing mix pad, the goods were again dried on atenter frame so as to control the width of the finished goods.

As in the case of Example I, the last step of the process involvedshrinking of the fabric on a compressive shrinking machine so as tocontrol the residual shrinkage, primarily of the cotton content of theblend, and to provide a finished width of from 40" to 41".

When tested in the same manner as the fabric of Example I, the finishedgoods gave the following results:

Stretch Set Shrinkage Warp Filling Warp Filling Warp Filling NOTE!Shrinkage indicates a gain.

Example III A lot of 47" 3.47 128 x 82 35% cotton-65% Dacron fabric wasprocessed by the same procedure as the cotton- Kodcl blend of ExampleII, except that the width of the fabric after the Washing and drying was40%", and after the heat setting operation was 41". Testing in themanner previously described gave the following results:

Stretch Set Shrinkage Warp Filling Warp Filling Warp Filling :NOTEZShrinkage indicates a gain.

Example IV v A lot of 47" 2.30 1 05 x 52 35% cotton-65% Dacron fabricwas also processed in the same manner as described in Example II, exceptthat'the width of the fabric after washing and drying was 44", thefabric after padding through the bluing mix'was dried with the tenterframe set at 45 /2", and the width of the goods after the heat settingoperation was 43 /2". When tested as described in Example I, thefollowing results were obtained:

Stretch Set Shrinkage Warp Filling Warp Filling Warp Filling NOTE:Shrinkage indicates a gain.

It will be seen from the foregoing examples that the method of thepresent invention is capable of imparting high stretch and low permanentset characteristics in the filling direction to cotton-polyester blendfabrics of vari- 7 ous standard constructions, producing a stretch offrom 15% to 30% of the finished width with a relatively high recovery.

While the starting fabric used in each of the examples was a standardgreige construction woven from standard twist yarns, it will be obviousthat the process is also applicable to reeded out and redesignedfabrics. In this connection, in order to provide a customer with astretchable woven cotton-polyester fabric in substantially the samewidth, weight and thread count as the standard nonstretchabLe goodsnormally desired by that customer for the specific end use involved, itwill usually be necessary to either reed out or redesign the greigeconstruction so as to allow for the increase in warp thread count anddensity or weight per unit length which results from the abnormalshrinkage produced by the present process. Economically, this wouldenable the use of a lighter and somewhat cheaper per square yard greigecloth which would still provide a stretchable finished fabricsufiiciently heavy for its ultimate end use. Alternatively, a greigeconstruction which is standard for one specific end use may be processedaccording to the invention so as to produce a stretchable fabric ofstandard specifications for a different end use.

Although specifically difierent procedures embodying the invention havebeen described in the foregoing examples, it should be clearlyunderstood that these examples are illustrative only and do not definethe limits of the invention, and that various changes in or additions tothe procedural steps described, which will be apparent to those skilledin the art, may be made without departing from the inventive concept.For example, it will be obvious that cross linking and auxiliary agentsother than those specifically mentioned may be used in the process forthe purpose of stabilizing the filling stretch characteristics,softening, coloring and otherwise improving the properties of thefinished fabric. It is equally obvious that the invention is applicableto woven cotton-polyester blend fabrics of widely varying weights andtypes, and that various degrees of stretch and recovery can be impartedto such fabrics to meet specifically different end use requirements.Furthermore, although the examples above described relate specificallyto bleached fabrics, it will be understood that the process also appliesto goods which are dyed to any desired color, preferably prior to theresin impregnating or heat setting phase of the procedure. Referenceshould therefore be had to the appended claims for a definition of thescope of the invention.

What is claimed is:

1. A process for treating fabrics Woven entirely from standard yarnsconsisting of a blend of cotton and polyester fibers to impart theretohigh stretch and recovery properties in the filling direction only whichcomprises the following steps:

(a) desizing the fabric;

(b) shrinking the desized fabric in the filling direction by subjectingit to the action of a mercerizing agent While maintaining the fabricunder tension in the warpwise direction and in .a substantiallyuntensioned condition in the filling direction;

(c) washing the fabric while maintaining it under tension in thewarpwise direction but without applying tension in the filling directionuntil substantially all of the mercerizing agent has been removed;

(d) drying the washed fabric without stretching in the fillingdirection;

(e) impregnating the dried fabric with a liquid mixture containing afluorescent dye and a wetting agent;

(f) drying the impregnated fabric while restricting shrinkage thereof inthe filling direction;

(g) heating the fabric to shrink and stabilize the polyester fibers ofthe filling yarns of the fabric while 8 maintaining the fabric undertension in the warpwise direction but without tension in the fillingdirection; and

(h) subjecting the fabric to a compressive shrinking operation tocontrol the residual shrinkage of the cotton fibers of the fabric.

2. A process according to claim 1 including, between steps (g) and (h),the additional steps of:

(i) impregnating the fabric with a liquid mixture containing a softenerand a white enhancing pigment; and

(j) drying the impregnated fabric while controlling the Width thereof-3. A process for treating fabrics woven entirely from standard yarnsconsisting of a blend of cotton and polyester fibers to impart theretohigh stretch and recovery properties in the filling direction only whichcomprises the following steps:

(a) wetting the fabric with an aqueous solution of sodium hydroxide ofmercerizing strength;

(b) maintaining the wetted fabric under tension in the warpwisedirection and in a substantially untensioned condition in the fillingdirection while the sodium hydroxide and the warpwise tension cause thefabric to shrink in width but not in length;

(0) washing thefabric to remove the sodium hydroxide while maintainingthe fabric under tension in the warpwise direction but leaving thefabric slack in the filling direction;

((1) drying the washed fabric while applying tension in the warpwisedirection 'but without increasing the width thereof; and

(e) heating the dried fabric at a sufficient temperature and fora'sufficient period of time to shrink and stabilize the polyester fibers of the filling yarns of the fabric while maintaining the fabricunder tension in the warpwise direction only.

4. A process as claimed in claim 3 including the additional step of:

(f) subjecting the fabric to a compressive shrinking operation tocontrol the residual shrinkage of the cotton fibers of the fabric.

5. A process as claimed in claim 3 including, between steps ((1) and(e), the additional steps of:

(g) impregnating the dried fabric with a liquid mixture containing asoftener and a white enhancing pigment; and

(h) drying the impregnated fabric while controlling the width thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,404,837 7/1946Goldthwait 139421 2,434,111 1/ 1948 Hawley et al. 28-74- X 2,477,652 8/1949 Robbins 161-92 2,491,396 12/1949 Seckel 161--92 2,774,129 12/1956Secrist 8-125 3,075,274 1/ 1963 Mizell 28-74' 3,086,274 4/1963 Arnett28-74 3,145,132 8/1964 Seltzer ..28--76 X 3,146,575 9/1964 Lund et al.28--76 X.

' FOREIGN PATENTS 649,666 10/ 1962 Canada.

- OTHER REFERENCES Du Pont Textile Fibers Dacron Polyester Fiber E. I. v

du Pont de Nemours and Co. Bulletin D-SQ, June 1955.

MERVIN STEIN, Primary Examiner. Y

MACKEY,

DONALD W. PARKER, ROBERT R.

. Examiners.

1. A PROCESS FOR TREATING FABRICS WOVEN ENTIRELY FROM STANDARD YARNSCONSISTING OF A BLEND OF COTTON AND POLYESTERS FIBERS TO IMPART THERETOHIGH STRETCH AND RECOVERY PROPERTIES IN THE FILLING DIRECTION ONLY WHICHCOMPRISES THE FOLLOWING STEPS: (A) DESIZING THE FABRIC; (B) SHRINKINGTHE DESIZED FABRIC IN THE FILLING DIRECTION BY SUBJECTING IT TO THEACTION OF A MERCERIZING AGENT WHILE MAINTAINING THE FABRIC UNDER TENSIONIN THE WRAPWISE DIRECTION AND IN A SUBSTANTIALLY UNTENSIONED CONDITIONIN TH FILLING DIRECTION; (C) WASHING THE FABRIC WHILE MAINTAINING ITUNDER TENSION IN THE WARPWISE DIRECTION BUT WITHOUT APPLYING TENSION INTHE FILLING DIRECTION UNTIL SUBSTANTIALLY ALL OF THE MERCERIZING AGENTHAS BEEN REMOVED; (D) DRYING THE WASHED FABRIC WITHOUT STRETCHING IN THEFILLING DIRECTION; (E) IMPREGNATING THE DRIED FABRIC WITH A LIQUIDMIXTURE CONTAINING A FLUORESCENT DYE AND A WETTING AGENT; (F) DRYING THEIMPREGNATED FABRIC WHILE RESTRICTING SHRINKAGE THEREOF IN THE FILLINGDIRECTION;